Polycarbonates are widely used engineering thermoplastics because they feature an attractive set of physical and mechanical properties. A disadvantage is, however, associated with their processing in that they have poor release properties. In injection molding application, this disadvantage translates to relatively long cycle times. Shorter cycle times have been attained by injection molding at higher temperatures and by using mold release agents. Long chain aliphatic carboxylic acid esters of monohydric and trihydric alcohols have been incorporated in poly-carbonate compositions to improve the release properties of the compositions: U.S. Pat. No. 4,007,150 disclosed the use of perfluoro-alkanesulphonic acid amides and/or cyclic ammonium salts of such acids as mold release agents. Relevant technology has been disclosed in U.S. Pat. No. 3,784,595 which refers to polycarbonate molding compositions having improved release properties containing an ester of trihydric alcohol and a C.sub.10-22 -saturated aliphatic carboxylic acid. These esters are said to be effective mold release agents, without at the same time causing a measurable quality lowering degradation of the polycarbonate. Also relevant in this context is U.S. Pat. No. 3,836,499 which disclosed esters of univalent C.sub.10-35 -alcohols and aliphatic saturated C.sub.8-25 -mono-carboxylic acids.